1. Field of the Invention
The present invention relates to a process for making biphenylene phosphites and bisphenylene phosphites, and more particularly relates to a process for making biphenylene phosphites and bisphenylene phosphites wherein solid product precipitation is formed without the need for invacuo solvent removal and residue recrystallization.
2. Description of the Related Art
Biphenytene phosphites and bisphenylene phosphites are generally known. Prior process for making such phosphites have generally involved the reaction of bisphenyl or biphenyl with phosphorous trichloride in the presence of a small amount of tri-n-alkylamine in an organic liquid medium (solvent) such as toluene. Following reaction, the resultant suspension is then filtered to remove tri-n-alkylamine hydrochloride and the liquid medium is removed invacuo. The residue is then recrystallized from an aliphatic solvent (heptane) to give fine white needs. An example of a typical prior process is set out in Paul A. Odorisio et al. "12H-Dibenzo (d,g) (1,3,2) Dioxaphosphocins: Synthesis and Evidence for Long-Range Coupling to Phosphorous" Phosphorus and Sulfur, 1983, vol. 15, pp. 9-13. Such processes undesirably require the multiple steps of filtration, vacuum removal of solvent and recrystallization of the bisphenyl/biphenyl phosphite product.
An improved process for making 3-9-diphosphaspiroundecanes was set out in Hobbs et al., U.S. Pat. No. 5,137,950, issued Aug. 11, 1992. The process involved reacting phosphorous trichloride with pentaerythritol and then reacting the product therefrom with a second hydroxyl-substituted organic compound in the presence of a tri-n-alkylamine in a molar amount equal to or greater than the molar amount of hydrogen chloride produced by the second reaction, wherein the phosphite produced is a solid product and is substantially insoluble in the medium of the second reaction. The reaction steps may be alternatively sequenced. The reference, however, neither shows nor suggests that such how to produce 2,2' biphenyl phosphide or 2,2'-bisphenyl phosphites.
Accordingly, there is a desire to provide a process to produce 2,2'-bisphenyl phosphites and/or 2,2'-bisphenyl phosphite without the need to recrystallize the product.